I work as a (non-fiction) editor and proofreader, and it is sadly true that in a few rare cases we do get fined for errors in important texts such as medical ones. Luckily it is very rare now that so many are involved in publishing each text.
As for 'just deserts': Our English word 'dessert' comes from a French word meaning “to remove what has been served” or de-serve: desservir.
'Deserts' here is the plural of 'desert', meaning 'that which one deserves'. 'Desert' in this sense is now archaic and rarely used outside this phrase.
Hence the confusion, I suppose. I keep wondering about doing a fiction editing course, but most trade publishers don't bother that much, as we have seen!